4i6 RESEARCHES ON FUNGI 



filiform hyphae. (4) The large clavate palisade cells at the margin 

 of the pileus of the agaric are fimbriate and thus correspond to the 

 very similar cells which occur on the exterior of the apophysis of a 

 stilbum-hody, i.e. on a structure which may be regarded as forming 

 the outer margin of a stilbum-head. (5) The spaces between the 

 hyphae in a head of a stilbum-hody and the spaces between 

 the hyphae of the flesh of a pileus are both filled with mucilage. 

 (6) The position of the annular air-chamber enclosed between the 

 apophysis and the upper end of the stalk of a stilbum-hody corre- 

 sponds to the position of the gills in a young pileus. These re- 

 semblances and also the occurrence of what Maublanc and Rangel 

 took to be intermediate forms ^ between the stilbum-hodies and the 

 perfect sporophores led these authors to the conclusion that the 

 stilbum-hodies are nothing but aborted Omphalia fruit-bodies. 



The view that the stilbum-hodies have been derived from the 

 rudiments of Omphalia fruit-bodies appears to me to be well based. 

 Many Hymenomycetes produce far more fruit-body rudiments than 

 ever come to perfection ; and it seems likely that, in Omphalia 

 flavida, in the course of evolution, some of the rudiments have become 

 progressively metamorphosed by means of structural and physio- 

 logical changes so as to fit them for liberating their aborted pilei 

 and thus disseminating the species in a novel but very effective 

 manner. 



The Stilbum-body as a Gemmifer. — The stilbum-hody, whatever 

 its origin in the course of evolution, is to-day an effective organ for 

 bringing about the dissemination of Omphalia flavida from place to 

 place, and it performs this function by liberating its tiny head. 

 This is blown, splashed, or otherwise carried from diseased leaves to 

 healthy ones, the latter readily becoming infected by means of the 

 long filiform filaments — which we may call the infection hyphae — 

 which radiate from the surface of the head and at once renew their 

 growth when a head becomes attached by its gelatinous envelope to 

 a new host-leaf. 



The name stilbum-hody is a misnomer ; for, as we have seen, a 

 stilbum-hody has nothing to do with a true Stilbum. A stilbum- 



1 Intermediate forms between stilbum-hodies and perfect agarics have not been 

 observed by either Ashby {loc. cit., p. 328) or myself. 



